Aural instrument.



No. 723,929. PATENTED MAR. 31, 1903..

R. M. SHAPPER.

AURAL INSTRUMENT.

APILIGATION FILED JUNE A1, 1902.

X0 MODEL.

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` UNITED STATES PATENT OFFICE.

RICHARD M. SHAFFER, OF BALTIMORE, MARYLAND, ASSIGNOR TO PAUL HINES AND.I. ALBERT SHAFFER, OF VASHINGTON, DISTRICT OF OO- LUMBIA.

AU RAL INSTRUM ENT.

3lEClIFIGAT0N forming part of` Letters Patent No. 723,929, dated March31, 1903. Application filed June 4,1902. Serial No. 110,225. (No model.)

iro all whom, t may concern:

Beit known that I, RICHARD M SHAFEER, ot' Baltimore, in the State ofMaryland, have invented certain new and useful Improvements in AuralInstruments; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

The object of this invention is to provide an aural instrument orear-trumpet so constructed as to receive and transmit a maximum volumeof sound and at the same time one which will occupy but little space andmay be conveniently carried in the hand or pocket of theA user.

The inventionwill be hereinafter fully set forth, and particularlypointed out in the claims. I

In the accompanying drawings, Figure lis a vertical longitudinalsectional view. Fig. 2 is a crosssectional view on line 2 2, Fig. l.Fig. 3 isa view of the sounding-head detached. Fig. lis a similar viewof the sound-conveyer.

Referring to the drawings, l designates the sound-receiver, whichis ofcylindrical formation throughout its length, its receiving end beingcovered by a perforated plate or diaphragm 2 to prevent the entrance offoreign matter or objects and also to somewhat break or expand thesound-waves. The other end of the receiver is closed by a sounding-head3, which head is made of thin metal and slightly arched, as at 4, inthat portion in line with the bore of the cylinder and expanded orbulged outwardly, as at 5, a short distance beyond the wall of thereceiver. By thus forming the sounding-head the greatest possiblevibratory eect is obtained, the soundwaves passing through the receiverstriking against the head and being immediately disseminated withincreased resonance.

6 is the sound-wave conveyer for receiving the sound from thesounding-head and conveying it to the ear of a person. This conveyer isin the form of a horn-like tube gradually tapered throughout itslength,with its `widened or enlarged end facing the soundinghead. It ispositioned longitudinally within the receiver and is bent back uponitself,

forming two approximately parallel members, one of which is carried tonear the receiving end ot' the other and again bent or carried nearlyobliquely across the latter and passed out through an opening in thereceiver below the sounding-head 3. Its projecting end has securedthereon a non-metallic earpiece 7. By thus bending the tube back uponitself and thence crosswise the tube occupies but little space in thereceiver, leaving an uninterrupted passage-way for the sound waves inbeing transmitted to vthe sounding-head, while the conveyer, beingcarried out of the cylinder below the soundinghead, leaves anuninterrupted space between the latter and the enlarged end ot` theconveyer, thus insuring the sound-waves being transmitted direct fromthe sounding-head into the conveyer. To this arrangement is very largelydue the high resonance obtained by my instrument.

To prevent trembling or too great vibration, the two members of the tubeare throughout a portion of their parallelism braced by a connecting-web8. Without this web, the tube being of very thin metal, the resonanceproduced by the sounding-head would cause a trembling of the tube by thevibration of the sound-waves, whereas this is lessened by bracing thetwo parallel portions.

The advantages of my invention are apparent. By locating theconveyer-tube to one side of the cylinder, leaving uninterrupted spacefor the passage of the sound, and by forming the sounding-head in themanner stated and in the described relation to the conveyer, an improvedand highly-efficient aural instrument is produced. Further advantageresides in thefact that the soundwaves enter the cylinder in thedirection of its longitudinal axis, thus insuring their full contactwiththe sounding-head.

I claim as my inventionl. An aural instrument or ear-trumpet, comprisinga receiver of cylindrical formation 95 having at one end a sounding-headslightly arched and bulged outwardly beyond the Wall of the receiver,and a sound-conveying tube located Within the receiver, at one sidethereof, and having its receiving end facing the loo arched portion ofthe sounding-head, and its other end extendedrroutwardly through thereceiver below the sou nding-head, as set forth.

2. An aural instrument or ear-trumpet, comprisinga receiver ofcylindrical formation having at one end a sounding-head slightly archedand bnlged outwardlybeyon d the Wall of the receiver, and asound-conveying tube located within the receiver at one side thereof,and consisting of a tube'bent back upon itself and thence carriedcrosswise and extended out ofthe receiver below the soundinghead, thereceiving end of the tube facing the arched portion of thesounding-head, as set forth. .i Y

3. An aural instrument comprising a receiver of cylindrical formationthroughout its length, a sounding-head over one end of the receiver ofthin metal arched throughout that portion in line with the bore of thecylinder and bulged outwardly beyond the wall of the latter,andasound-conveyer facingthe sounding-head at its receiving end andextending, at its other end, through the wall of the reeeiver below thesounding-head, as set forth.

4. An aural instrument comprising a receiver of cylindrical formationthroughout its length, a sounding-head over one end of the receiverofthin metal arched throughoutrthat portion in line with the bore of thecylinder and rounded or hulged outwardly beyond the Wall thereof, and asoundcouveying tube of thin metal tapered throughout its lengthfand bentback upon itselfand thence carried crosswise terminating outside of thereceiver, Yand a bracing-Web connecting the two members of the tube,substantially as set forth.

5. An aural instrument comprising a receiver of cylindrical formationopen at its receiving end, a sounding-head over the oppo- Site end ofthe receiver arched throughout that portion in line with the bore ofthecylinder and rounded or bulged outwardly beyond the Wall thereof, anda sound-conveying tube located within the receiver and having itsreceiving end facing the arched portion of the sounding-head and itsother end extended outwardly through the receiveibelowY thesounding-head, substantially as set forth.

In testimony whereof I have signedthis specification in the presence oftwo subscribingwitnesses. j

RICHARD M. SHAFFER. Witnesses:

BERNARD A. SCHMITZ, WM. M. WHITE.

